Лох-Морар: Глубочайшее озеро Великобритании и его особенности.

A lake in Lochaber, Scotland
the steamship

Loch Morar is long, has a surface area of , and is the deepest freshwater body in the British Isles with a maximum depth of 1017 feet (310 m). In 1910, John Murray and Laurence Pullar found it to have a mean depth of 284 feet (87 m) and a total volume of during their survey of Scottish lochs. The bottom is deepened below the United Kingdom Continental Shelf, and until 1943, when a depth of 1062 feet (324 m) was observed in the Inner Sound, it was believed to be the deepest water in the United Kingdom. The surface of the loch is above sea level. The water of the loch is clear and oligotrophic, with a minimal intake of nutrients, making it a Site of Special Scientific Interest (SSSI). The main inflow is the River Meoble on the southern side, which drains from Loch Beoraid, although there are three other major inflows at the eastern end of the loch and a stream draining a complex of lochans to the north west of Loch Morar. At the shallower western end of the loch, there are a number of sizeable forested islands. Swordland Lodge, on the northern shore of the loch, was used as training school STS 23b during the Second World War by the Special Operations Executive. A 750 kW hydroelectric power station with a hydraulic head of was built on the River Morar and commissioned in 1948.

At the western end of the loch is the village of Morar, which is between Arisaig and Mallaig on the coastal A830 road. The settlements of Bracorina and Bracara are located along the northern shore of the loch, but there is no road along the southern shore. Boats left in 1790, and 1826, carrying people to Quebec, Glengarry in Ontario, and the Strait of Canso in Nova Scotia respectively.

Loch Morar is located entirely within the Morar Group of sediments, which were deposited in the latter part of the Cambrian, and subsequently subjected to many phases of deformation. The loch occupies a basin produced by the overdeepening of the valley by glacial erosion, along an east west fault line. It is not a sea loch due to isostatic rebound that raised the rock sill at the end of the loch. Based on estimates of erosion of between per year, the deep basin was created over a period of 67,000 – 150,000 years of glacial action, which occurred intermittently during the last million years of the Quaternary glaciation. Subsequently, colonised by vegetation and known as Mointeach Mhòr (the mossy plain), these deposits blocked the outflow of the loch to the south, so that it drained from the north west corner instead. The catchment area of the loch is , and the geology is base poor. A site to the north of the loch was selected in 2011 as a SSSI for its characteristic rock exposures of the Moine group by the Geological Conservation Review, replacing the area around Mallaig harbour, which had been previously regarded as the most representative site.

The loch is surrounded by a mix of natural woodland, open hillside, sheep and cattle pasture and planted mixed coniferous and broadleaf woodlands. Only around 0.7% of the surface of the loch can be colonised by plants. Trout average around in size, but ferox trout of up to have been caught. The loch is also known to contain eels, although none were caught in a recent survey of eel populations in Lochaber, suggesting that they prefer the loch to the tributaries surveyed. Catches of salmon and sea trout declined dramatically between the 1970s and 1980s, in common with other catchments on the west coast. Artificial stocking of the River Morar with salmon and sea trout was suspended in 2007 after the hatchery was closed.